Acta Dermato-Venereologica 99-1CompleteContent | Page 20

78 INVESTIGATIVE REPORT Granular IgA Deposits in the Skin of Patients with Coeliac Disease: Is it Always Dermatitis Herpetiformis? Veronica BONCIOLINI 1 , Emiliano ANTIGA 1 , Beatrice BIANCHI 1 , Elena DEL BIANCO 1 , Alessandra NINCI 1 , Vincenza MAIO 2 , Nicola PIMPINELLI 1 and Marzia CAPRONI 1 Department of Surgery and Translational Medicine, 1 Section of Dermatology, and 2 Section of Pathological Anatomy, University of Florence, Florence, Italy Coeliac disease is an immune-mediated enteropathy driven by gluten, which can be associated with derma- titis herpetiformis. The presence of granular IgA de- posits, detected by direct immunofluorescence, is the hallmark of dermatitis herpetiformis; nevertheless, IgA deposits have also been demonstrated in healthy skin of patients with coeliac disease. The main objec- tive of this study was to investigate whether IgA depo- sits could be found in the skin of patients with coeliac disease who have non-dermatitis herpetiformis inflam- matory skin diseases. Direct immunofluorescence was performed on perilesional skin biopsies of 6 patients with coeliac disease with non-dermatitis herpetifor- mis inflammatory skin diseases and, as control, on 12 non-coeliac patients with inflammatory skin diseases. IgA deposits were found in all of the patients with co- eliac disease, but were absent in the control group. In conclusion, IgA deposits may be considered an immu- nopathological marker for coeliac disease; therefore, patients with coeliac disease showing skin manifesta- tions with positive direct immunofluorescence should be investigated carefully in order to make a differen- tial diagnosis between dermatitis herpetiformis and other non-dermatitis herpetiformis inflammatory skin diseases. Key words: coeliac disease; skin IgA deposits; skin manifesta- tions of coeliac disease. Accepted Jul 3, 2018; Epub ahead of print Jul 4, 2018 Acta Derm Venereol 2019; 99: 78–83. Corr: Veronica Bonciolini, Department of Surgery and Translational Medi- cine, Section of Dermatology, University of Florence, Viale Michelangiolo, 41, IT-50129 Florence, Italy. E-mail: [email protected] C oeliac disease (CD) can be defined as an autoim- mune disorder where the ingestion of wheat gliadins and other cereal prolamins leads to demage in the small intestine in genetically susceptible individuals (1). The pathogenetic mechanism is related to a T-cell response against an external trigger, the gluten peptides, and to the ubiquitous enzyme tissue transglutaminase, which, as autoantigen (2), enhances the immunogenicity of gluten peptides (3–5). Several extraintestinal manifestations of CD affect different organs and systems; among them, many muco- cutaneous diseases have been described (6). In particular, dermatitis herpetiformis (DH) is considered to be a speci- doi: 10.2340/00015555-3001 Acta Derm Venereol 2019; 99: 78–83 SIGNIFICANCE Coeliac disease is a chronic enteropathy characterized by a permanent intolerance to gluten that is frequently as- sociated with several extraintestinal conditions, including skin diseases. Dermatitis herpetiformis is the specific cu- taneous manifestation of coeliac disease; however, many other dermatoses are reported in celiac patients. The im- munopathologic hallmark of dermatitis herpetiformis is the presence of IgA deposits at the dermal–epidermal junction of perilesional skin as detected by direct immunofluores- cence. Our study showed that such deposits can be found also in celiac patients with inflammatory skin diseases dif- ferent from dermatitis herpetiformis and, therefore, could be considered as a marker of coeliac disease. fic cutaneous manifestation of CD, although several other inflammatory skin diseases have been shown to be more frequent in patients with CD, including psoriasis, atopic dermatitis, alopecia areata, chronic urticaria, chronic ulcerative stomatitis, etc. (6). The presence of granular IgA deposits along the ba- sement membrane, with accentuation at the tips of the dermal papillae, seen on direct immunofluorescence (DIF) of uninvolved skin, is the pathognomonic im- munological marker of DH (7–11). Despite minor and not-critical differences in the pattern, in the localization and in the composition of the immune deposits, due to its high specificity, this finding represents the gold standard for diagnosis of DH. In 2007, Cannistraci et al. (12) also showed the pre- sence of granular IgA deposits in the healthy skin of patients with CD, who were not affected by any skin diseases, suggesting that such deposits could be con- sidered not only a marker of DH, but, more generally, of CD. Thus, the main objective of this study was to investigate whether IgA deposits can be found not only in the healthy skin of patients with CD, but also in non-DH inflammatory skin diseases of such patients. METHODS Study design In order to assess whether IgA deposits could be found in pa- tients with CD who have non-DH inflammatory skin diseases, a comparative prospective study was conducted on patients with This is an open access article under the CC BY-NC license. www.medicaljournals.se/acta Journal Compilation © 2019 Acta Dermato-Venereologica.